NASA brought the Mariner R-2 spacecraft out of storage and launched it just 36 days after the failure of Mariner 1. Mariner 2, as it was known after launch, was equipped with an identical complement of instrumentation to that of its predecessor (see Mariner 1).

The mission proved to be the first fully successful interplanetary mission performed by any nation. After a midcourse correction on 4 September, the spacecraft flew by Venus at a range of 34,762 km on 14 December 1962. During a 42-minute scan of the planet, Mariner 2 gathered significant data on the Venusian atmosphere and surface before continuing on to heliocentric orbit.

NASA maintained contact until 07:00 UT on 3 January 1963, when the spacecraft was 87.4 million kilometers from Earth, a new record for a deep space probe. The data returned showed that the surface temperature on Venus was at least 797 degrees Fahrenheit (425 degrees Celsius) with minimal differentiation between the day and night sides of the planet. Mariner 2 also found that there was a dense cloud layer that extended from 56 to 80 km above the surface. The spacecraft detected no discernible planetary magnetic field; this lack is partly explained by the great distance of the flyby.

After this successful mission, NASA elected to stand down the third spacecraft in the series (Mariner R-3), scheduled for the 1964 launch window.

Key Dates

27 Aug 1962: Launch (06:53:14 UT)

14 Dec 1962: Venus Flyby

3 Jan 1963: Contact Lost

Status: Successful

Fast Facts

Mariner 2's success was celebrated with a float in the 1963 Tournament of Roses Parade (right).

The spacecraft lost attitude control en route to Venus, possibly due to collision with a small meteoroid. Gyroscopes restored control after 3 minutes.

A similar 1964 mission in the series was not used due to Mariner 2's success.

People Spotlight

Carl SaganAstronomer Carl Sagan was often described as "the scientist who made the Universe clearer to the ordinary person."